Video: Did 9/11 hijackers have U.S. helpers?

WASHINGTON — It's one of the most pressing questions after the 9/11 terrorist attacks: Did the 19 hijackers have any accomplices inside the United States? The FBI has always said "no," but NBC News has learned that because of new information, the FBI has now renewed its investigation of a man the 9/11 Commission said was "perfectly suited" to help the hijackers with their mission.

Senior U.S. law enforcement officials tell NBC News that the FBI is again actively investigating a good friend of the 9/11 hijackers — two years after the U.S. allowed the man to be deported to his home country.

His name is Mohdar Abdullah, a Yemeni student who admits befriending two 9/11 hijackers — Nawaf Al-Hazmi and Khalid al-Mihdhar — when they lived in San Diego.

NBC News has learned that the renewed FBI investigation was triggered, in part, by surveillance videotapes from inside the Los Angeles Airport shot in June 2000 — a year before 9/11.

Law enforcement officials tell NBC the grainy tapes show terrorist Nawaf al-Hazmi with Abdullah and an unidentified man. Sources say the men appear to be scouting out the airport. Some FBI agents believe that one of the men may be holding a video camera and rotates in a circle while secretly videotaping near the security area.

"This is very consistent with what the hijackers did," says 9/11 Commission former co-chair Tom Kean, adding, "if he's on tape here with the hijackers, then this is something that should really be investigated further."

No chance to quiz suspect
The 9/11 Commission says Abdullah had extremist sympathies, helped the two hijackers get drivers licenses and flight training and, after 9/11, "expressed hatred for the U.S. government."

Some law enforcement officials now regret deporting Abdullah. One official tells NBC he is now "more suspicious" that Abdullah had some prior knowledge of the 9/11 attacks.

But in an exclusive interview with NBC in 2004, Abdullah said the hijackers tricked him.

"They never even mentioned they had training before," Abdullah said. "They didn't mention they have such hatred to the United States."

Abdullah's former lawyer, Randall Hamud, tells NBC that his client never knew the hijackers were here to harm the U.S. He says that the FBI has thoroughly investigated the case, and that the U.S. never would have deported Abdullah to Yemen if he had been guilty of knowingly supporting the 9/11 terrorists.

As to the LAX videotape, Hamud suggests there may be an innocent explanation:

"The problem is that in the paranoid times today, a lot of law enforcement people and Americans think that any Arab, Muslim, or South Asian carrying a video camera is a terrorist up to no good," Hamud says. "I have seen no information or evidence to indicate that Mohdar Abdullah was anything other than an innocent victim of the two hijackers who duped him, along with a lot of other people in the San Diego, as to why they were here."

Law-enforcement officials tell NBC News that the FBI is now re-examining all of Abdullah's contacts with friends and associates in the U.S., especially anyone he's contacted since returning to Yemen.

FBI Assistant Director John Miller issued the following statement to NBC News:"At the time of his release, the FBI did not have sufficient evidence to charge [Mohdar Abdullah] with a crime. ICE did not have a legal basis to hold him indefinitely. Since deporting him, through investigation, the FBI has uncovered some additional information but not enough on its own to bring any formal charge. We continue to examine the contacts between the 19 hijackers and a number of persons."

Why didn't they find these tapes until 2004 isn’t known — especially since the FBI knew that on the day these tapes were shot in June 2000, one of the hijackers went to Los Angeles Airport for a flight home to Yemen. Critics are certain to question whether the FBI again missed an important clue, and let a possible accomplice get away.